Transcripción del resumen del autor. Managed Pressure Drilling (MPD) is an advanced form of primary well control usually employing a closed and pressurizable drilling fluids system that allows more precise control of the wellbore pressure profiles than mud weight and mud pump rate adjustments alone. Unlike conventional opento- atmosphere mud returns systems at the rig floor such as drilling or bell nipples, the circulating fluids system employed by MPD technology is more akin to that of a pressure vessel. Although the term, Managed Pressure Drilling or MPD is relatively new to the industry, having been first introduced in this context at the 2004 IADC/SPE Amsterdam Drilling Conference, the practice itself is not and it have been evolving on land programs over the past two decades. This is particularly true in the United States where 3 out of 4 land drilling programs drill at least one section with a closed and pressurizable mud returns system, up from 1 in 10 in 1995. At the essence of MPD is the ability to apply surface backpressure while drilling ahead or shut in to make jointed pipe connections. Drill string non-return valves, a rotating control device, and a dedicated choke manifold are the basic tools required. Some applications of MPD may require other tools and technology developed and proven for the safe practice of UBD. As if necessity is the mother of invention, these techniques enabled by drilling with a closed and pressurizable mud returns system have been driven by desires to reduce drilling non-productive time associated with drilling-related issues such as: ~ Narrow fracture to pore pressure "windows" and the associated kick-loss and well control scenarios, ~Loss circulation & associated excessive mud costs, ~Excessive casing programs, ~Slow Rate of Penetration (ROP), ~Well control issues, and ~Failure to reach TD with large enough hole.